Frequently Asked Questions About Mack CH/CHN/CHU Universal Elbows & Piping

What size exhaust elbow do I need for my Mack CH series truck?

Most Mack CH, CHN, and CHU models from 1988-2007 use 5-inch diameter exhaust systems as standard. However, some models came with 4-inch systems, particularly earlier years or lower-spec engines. To determine your size, measure the outer diameter of your current exhaust pipe or check the specs on your engine model. E3 and E7 engines typically use 5-inch, while some E6 engines may have 4-inch systems.

Are these elbows made from aluminized or stainless steel, and which should I choose?

We offer both aluminized steel and stainless steel options. Aluminized steel elbows provide good corrosion resistance at a lower price point and typically last 3-5 years depending on your operating conditions. Stainless steel elbows (usually 409 or 304 grade) offer superior longevity of 7-10+ years and better heat resistance, making them ideal for heavy-duty applications or coastal areas with salt exposure. Choose based on your budget and how long you plan to keep the truck.

Will universal elbows fit my specific Mack model year without modification?

Universal elbows are designed to fit all Mack CH, CHN, and CHU models from 1988-2007 with the same diameter exhaust system. However, some fitting adjustments may be needed depending on your specific configuration. Models with aftermarket modifications, different muffler setups, or custom stacks may require additional adapters or slight angle adjustments during installation. We recommend having clamps and possibly a short straight pipe section on hand for installation.

What angle elbow do I need - 45, 60, or 90 degree?

The angle depends on your exhaust routing and stack configuration. Most vertical stack setups use 90-degree elbows to make the turn from horizontal to vertical. If you have a curved or swept-back stack design, 45 or 60-degree elbows work better. For under-frame exhaust exits, 45-degree elbows are most common. Check your current setup or measure the angle needed with a protractor against your frame rail to determine the best fit.

Do I need special clamps or gaskets when installing these elbows?

Yes, proper clamps are essential for a leak-free installation. We recommend using heavy-duty exhaust clamps rated for your pipe diameter (4 or 5-inch). Avoid standard U-bolt clamps as they can deform the pipe - use wide band clamps or V-band clamps for best results. Gaskets are typically not needed for slip-fit connections, but apply high-temp exhaust sealant to the joints for added security against leaks, especially on aluminized steel connections.